Text boxes with bbox in Matplotlib - Time & Space Complexity

Time Complexity: Text boxes with bbox

O(n)

Understanding Time Complexity

We want to understand how the time needed to draw text boxes with backgrounds changes as we add more boxes.

How does the drawing time grow when we increase the number of text boxes?

Scenario Under Consideration

Analyze the time complexity of the following code snippet.

import matplotlib.pyplot as plt

fig, ax = plt.subplots()
n = 10  # Example value for n
for i in range(n):
    ax.text(i, i, f"Box {i}", bbox=dict(facecolor='yellow', alpha=0.5))
plt.show()

This code draws n text boxes with colored backgrounds on a plot.

Identify Repeating Operations

Identify the loops, recursion, array traversals that repeat.

• Primary operation: Drawing each text box with a background.
• How many times: The loop runs n times, once per text box.

How Execution Grows With Input

Each additional text box adds a similar amount of drawing work.

Input Size (n)	Approx. Operations
10	10 drawing operations
100	100 drawing operations
1000	1000 drawing operations

Pattern observation: The work grows directly with the number of text boxes.

Final Time Complexity

Time Complexity: O(n)

This means the time to draw grows in a straight line as you add more text boxes.

Common Mistake

[X] Wrong: "Adding more text boxes won't affect drawing time much because they are simple."

[OK] Correct: Each text box requires separate drawing work, so more boxes mean more time.

Interview Connect

Understanding how drawing time grows helps you write efficient visualization code and explain performance in real projects.

Self-Check

"What if we added nested loops to draw multiple text boxes at each position? How would the time complexity change?"